Spark split text performance tuning? - scala

Question

I need parse text with spark
text file:
Struct{event=x,key=x,cas=x,content={"recordData":{JSON}}
i used my udf but spark executor oom killed and finish task .How can I improve performance?
def getKafkaMessageHeader = udf((sampleDF: Column) => {
val segments: Array[String] = sampleDF.toString().split("content=", 2)
val output: util.Map[String, String] = new util.HashMap[String, String]
var tmp: String = null
if (segments.length == 2) {
tmp = StringUtils.substringBetween(segments(0), "cas=", ",")
output.put("cas", StringUtils.substring(tmp, 0, 16))
output.put("event", StringUtils.substringBetween(segments(0), "event=", ","))
output.put("key", StringUtils.substringBetween(segments(0), "key=", ","))
output.put("content", StringUtils.chop(segments(1)))
}
else if (segments.length == 1) {
tmp = StringUtils.substringBetween(segments(0), "cas=", "}")
output.put("cas", StringUtils.substring(tmp, 0, 16))
output.put("event", StringUtils.substringBetween(segments(0), "event=", ","))
output.put("key", StringUtils.substringBetween(segments(0), "key=", ","))
output.put("content", null)
}
else {
output.put("cas", null)
output.put("event", null)
output.put("key", null)
output.put("content", null)
}
val recordData = new recordData()
cas = output.get("cas")
event= output.get("event")
key= output.get("key")
content= output.get("content")
})